"Sickle cell disease" refers to a group of inherited hematologic disorders characterized by a point mutation in the beta globin gene on chromosome 11. When both beta globin genes have the sickle mutation, the patient has homozygous sickle cell anemia (Hb SS). Upon deoxygenation, HbS polymerizes within the erythrocyte to form large tactoids which cause a deformation of the cell membrane. Due to blockage of small capillaries by these deformed erythrocytes, there is acute and chronic organ damage due to vaso-occlusion. Patients with sickle cell disease often have chronic pain throughout life, and multiorgan failure upon reaching adulthood. Patients with sickle cell anemia with high fetal hemoglobin (Hb F) have fewer clinical problems than those with low Hb F. Accordingly, there has been intense interest in the pharmacologic manipulation of the gamma globin genes. Recently, treatment with hydroxyurea has been shown to improve both the absolute amount and the distribution of Hb F within the erythrocytes of adults with sickle cell anemia. Butyrate therapy has been shown to increase Hb F in a few adults with sickle cell disease and thalassemia. This trial will study 1) the pharmacokinetics of compound VX-105 (arginine butyrate) in children with sickle cell anemia, 2) the safety of VX-105 infusions in children with sickle cell anemia and 3) the efficacy of infusions with VX-105 on hematologic parameters in children with sickle cell anemia. Fourteen patients were treated on this study on the GCRC. The data is being analyzed at the present time. The study is closed as per the industry sponsor, Vertex.